The present invention relates to a treating method and a treating apparatus of a used cell or battery, and to a method and an apparatus for treating a lithium cell.
Demands of cells or batteries are increasing year by year. Effective utilization of chemical substances employed in cells or batteries, and also problems of environmental pollution caused by cells or batteries must be considered. For example, lithium and transition metal element and the like employed in a lithium cell are valuable substances to be reused. Rechargeable lithium secondary cells are extensively used year after year as backup power sources for computers and power sources for compact home appliances. Other demands as power storage power sources, or power sources for automobiles may have a bright future.
High energy type cells typically known as lithium cells employ electrolytic solution containing negative-electrode activated substances such as reaction-activated alkali metals, and also substances reactive to water. And most of positive electrodes include great deal of reusable metal component. As a consequence, when used cells are dismantled, it is desired to propose such a treatment method that cell-activated substances, or activated substances such as electrolytic solution are brought into inert substances under safety states, and reusable valuable chemical substances are collected. However, no confirmation could be made about any method for treating a large number of cells such as used lithium cells in an industrial scale, or any invention related to a cell treating apparatus.
To suppress environmental pollution caused by chemical substances contained in used cells, or used batteries, and to improve utilization of resources employed in these cells, cell treating methods as well as methods for reusing cell materials have been required for long time.
Generally speaking, a specific care should be taken to handle such high-energy density type cells as lithium cells, because these cells contain cell activated substances or electrolyte with extremely high chemical reactive characteristics. For instance, carbon compounds into which a lithium metal, a lithium alloy, and lithium have been inserted by electrical and chemical methods, are utilized in a negative electrode of a lithium cell, and therefore any of these compounds extremely reacts to water, thereby producing hydrogen gas. Also in the above-described cells, there are employed other than the above-mentioned alkali metal, either valuable substances such as reusable transition metals, or electrolytic solution capable of probably producing poison gas. As an example of the valuable substances, there are LiCoO.sub.2, LiNiO.sub.2, V.sub.2 O.sub.5 and the like, which correspond to an activated substance of a positive electrode for a lithium cell. As an example of the electrolytic solution, there are LiPF.sub.6, LiAsF.sub.6 and the like, which correspond to the typical electrolyte of the lithium cell. The electrolytic solution containing these electrolyte mediums is resolved with being cooperative to water, thereby producing PF.sub.5, AsF.sub.5 and the like having strong poison. As a consequence, method/means capable of safely treating cells in a high efficiency are required.